Medical diagnostics company Alere Inc. said Monday that it bought a 6.4-percent stake in Axis-Shield PLC as part of an unsolicited $375 million offer for the company.
Alere said it has acquired a total of 3.2 million shares of Axis-Shield, which develops and makes in vitro diagnostic tests.
On Friday, Alere said it was making an offer for all shares of Axis-Shield. It said it would pay 460 pence ($7.51) per share for the company, and valued the deal at $375 million. Axis-Shield said the offer undervalues the company.
The sale will be completed if Alere is able to buy a total of 90 percent of Axis-Shield shares. Axis-Shield is based in Norway and Scotland.
Alere shares lost 93 cents, or 3.6 percent, to $25 as the markets opened lower.